| The proportional flow valve control system is the most popular method among the control system of hydraulic elevators. The proportional flow valve control system with speed-electric feedback applied in hydraulic elevators can eliminate disturbances of nonlinear source such as oil temperature and load change. In this system, the proportional valve plays a key role. Therefore, it is of significance to develop new relevant proportional valve specially applied in hydraulic elevators.This thesis mainly deals with the theoretical analysis, design, simulation and experimental research of integrated control valve.In chapter 1, the development history and present situation of control technologies of the hydraulic elevators in domestic and overseas, are briefly reviewed. Some typical control systems are reviewed and the design scheme and main tasks are presented.In chapter 2, the principle of electro-hydraulic proportional flow valve with speed-electric feedback applied in hydraulic elevators are analyzed. Based on the work of the predecessors in the hydraulic-elevator projects, two proportional flow valves are introduced, one is in charge of the up task of the elevator and the other in charge of the down control. The structure features, working principles of the integrated valve are described in details. The static and dynamic mathematical models of the integrated valve are derived.In chapter 3, the design of each components of the integrated valve are introduced, which include the design of up and down main valves, pilot valves, single way valve and manual urgent descending valve and the safety valve. A 3-D Computer Aided Design (CAD) software, Pro/Engineer, is applied in solid modeling, assembly, structure analyzing and dynamic interference checking. It is very useful to lay out components, hydraulic resistances and oil ways of the integrated valve. Consequently, the quality and performance of the integrated valve will be improved.In chapter 4, by the tool of Matlab/Simulink, static and dynamic simulation researches for up and down hydraulic circuit of the integrated valve are given. There are two important points in static simulation research work, one is static regulation range, and the other is dead-zone. In dynamic simulation research, variable parameters and optimum simulation research work for the integrated valve are made.In chapter 5, the experiment researches of the integrated valve are introduced. After completing the static and dynamic experiments on the5 Electro-Hydraulic Component & System Test Unit, the author made further experiment research in the close loop system of hydraulic elevator, and get satisfying testing results.To sum up, the author build a set of theories and formulary for the design of integrated valve, change the traditional methods for the structure design of hydraulic elevator valves by the tools of PRO/E, carry out a lot tests of the integrated valve on the special test platform. The work greatly boost the development of proportional valve control system applying car speed feedback and the development and spread of homemade hydraulic products. |
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